First report on the safety and efficacy of an extended half-life glycoPEGylated recombinant FVIII for major surgery in severe haemophilia A

BACKGROUND

N8-GP (turoctocog alfa pegol) is an extended half-life glycoPEGylated recombinant factor VIII (FVIII) product developed for the prevention and treatment of bleeds in haemophilia A patients.

AIM

This is a planned interim analysis of pathfinder™3, an international, open-label, Phase 3 trial evaluating the efficacy and safety (including immunogenicity) of N8-GP administered before, during and after major surgery in severe haemophilia A patients aged ≥12 years.

METHODS

Sixteen patients who underwent 18 major surgical procedures (including synovectomy, joint replacement and ankle arthrodesis) were included here. Postoperative assessments were conducted daily for days 1-6, and once for days 7-14. Primary endpoint was N8-GP haemostatic efficacy, assessed after completion of surgery using a four-point scale ('excellent', 'good', 'moderate', 'none').

RESULTS

Haemostasis was successful (rated 'excellent' or 'good') on completion of surgery in 17 (94.4%) procedures and rated as 'moderate' (5.6%) for one surgery in a patient with multiple comorbidities who needed an intraoperative N8-GP dose (20.7 IU kg^-1 ). In the postoperative period, three bleeds occurred (one during days 1-6; two during days 7-14); all were successfully treated with N8-GP. Mean N8-GP consumption on day of surgery was 80.0 IU kg^-1 ; patients received a mean of 1.7 doses (median: 2, range: 1-3). No safety concerns were identified.

CONCLUSION

The data showed that N8-GP was effective and well tolerated for the prevention and treatment of bleeds during major surgery; such FVIII products with extended half-lives may modify current treatment schedules, enabling fewer infusions and earlier patient discharge.

Usefulness of a simple self-administered joint condition assessment sheet to predict the need for orthopaedic intervention in the management of haemophilic arthropathy

INTRODUCTION

Detecting signs of joint deterioration is important for early effective orthopaedic intervention in managing haemophilic arthropathy.

AIM

We developed a simple, patient self-administered sheet to evaluate the joint condition, and assessed the predictive ability of this assessment sheet for the need for an orthopaedic intervention.

METHODS

This was a single-centre, cross-sectional study. The association between the score of each of the four items of the assessment sheet (bleeding, swelling, pain and physical impairment) and the results of radiological findings and physical examinations based on Haemophilia Joint Health Score 2.1 was assessed. An optimal scoring system was explored by the area under the curve (AUC). The cut-off value for the need for surgery or physiotherapy was determined using the receiver operating characteristic curve procedure.

RESULTS

Forty-two patients were included. The 'physical impairment' item showed the highest correlation coefficient with the results of radiographic and physical examinations (range: 0.57-0.76). The AUC of finally adjusted scoring indicates good ability to discriminate between patients with and without a need for orthopaedic intervention. The positive predictive value was the highest at a cut-off value of 4 points for knees (63.0%) and ankles (70.0%), at 5 points for elbows (66.7%) and the highest predictive accuracy at the cut-off value of 4 points for all the joints. The linear trend of the need for an orthopaedic intervention was observed with an increasing score.

CONCLUSION

The joint condition assessment sheet can help clinicians assess the need for orthopaedic intervention for haemophilic arthropathy in Japanese patients with haemophilia.

The features of clearance in recombinant factor IX (BeneFIX(®) )

INTRODUCTION

Dosage adjustment is very important to perform continuous infusion (CI) of recombinant factor IX (rFIX) concentrates more effectively and economically, and clearance (CL) is strongly related to the infusion rate. However, previous reports have shown that the CL of rFIX concentrates varies widely (4.2-11.4 mL kg(-1) h(-1) ).

AIM

The goal of this study was to gain a better understanding of the CL of the rFIX concentrate (BeneFIX(®) ) to precisely set the infusion rate of rFIX concentrates.

METHODS

We estimated CLs by five different calculation approaches: from area under the blood concentration-time curve (AUC), from in vivo recovery (IVR) and half-life, from actual FIX activity value during CI, and from the simulation by one-compartment model in seven patients with haemophilia B.

RESULTS

The mean CL calculated from AUC was 3.8 ± 0.4 mL kg(-1) h(-1) (range = 3.3-4.3 mL kg(-1) h(-1) ).

CONCLUSION

The mean CL calculated from IVR and distribution half-life was 4.4 ± 0.4 mL kg(-1) h(-1) (range = 4.0-5.1 mL kg(-1) h(-1) ). The mean CL calculated from IVR and terminal half-life was 2.1 ± 0.5 mL kg(-1) h(-1) (range = 1.7-2.8 mL kg(-1) h(-1) ). The mean CL during CI was 4.9 ± 0.6 mL kg(-1) h(-1) (range = 4.2-5.6 mL kg(-1) h(-1) ). In addition, when we simulated the theoretical CL using a one-compartment model, the adjusted mean CL during CI was 4.8 ± 0.5 mL kg(-1) h(-1) (range = 4.0-5.4 mL kg(-1) h(-1) ). The CL obtained from distribution half-life was comparable to the CL during CI, while the CL calculated from terminal half-life did not reflect actual CL. Further, the rFIX concentrate was characterized by a one-compartment model under certain conditions.

Self-monitoring has potential for home exercise programmes in patients with haemophilia

Haemophiliacs who have had to keep a physically inactive lifestyle due to bleeding during childhood are likely to have little motivation for exercise. The purpose of this study is to clarify the effectiveness of the self-monitoring of home exercise for haemophiliacs. A randomized controlled trial was conducted with intervention over 8 weeks at four hospitals in Japan. Subjects included 32 male outpatients aged 26-64 years without an inhibitor who were randomly allocated to a self-monitoring group and a control group. Individual exercise guidance with physical activity for improvement of their knee functions was given to both groups. The self-monitoring materials included an activity monitor and a feedback system so that the self-monitoring group could send feedback via the Internet and cellular phone. The self-monitoring was performed by checking exercise adherence and physical activity levels, bleeding history and injection of a coagulation factor. Both groups showed significant improvements in exercise adherence (P < 0.001) and physical function such as the strength of knee extension (P < 0.001), range of knee extension (P < 0.001), range of ankle dorsiflexion (P < 0.01), a modified Functional Reach (P < 0.05) and 10 metre gait time (P < 0.01). In particular, improvements in exercise adherence (P < 0.05), self-efficacy (P < 0.05), and strength of knee extension (P < 0.05) were significant in the self-monitoring group compared with those in the control group. No increase in bleeding frequency and pain scale was noted. The self-monitoring of home exercise for haemophilic patients is useful for the improvement of exercise adherence, self-efficacy and knee extension strength.

The risk of elective orthopaedic surgery for haemophilia patients: Japanese single-centre experience

Haemophilic arthropathy causes pain and a severely restricted range of motion, and results in a significant reduction in quality of life. When conservative treatments have failed, orthopaedic surgery is recommended for these patients with severe haemophilic arthropathy. However, surgery for haemophilia patients is challenging due to high complication rate such as infection, delayed wound healing and mortality. The aim of this study was to evaluate the incidence of early complications and identify preoperative risk factors of surgery for haemophilia patients. We report a series of haemophilia patients undergoing elective orthopaedic surgery between 2006 and 2012. During this period, 119 surgeries in 81 patients were prepared and 118 surgeries in 80 patients were actually performed. Four deep bacterial infections and four delayed wound healings occurred within 6 months postoperatively. One patient died preoperatively and four patients died postoperatively. Only the presence of inhibitor was a significant risk factor for infection. We found no risk factor related to delayed wound healing. Our data revealed alkaline phosphatase, albumin, platelet, alpha-fetoprotein, presence of ascites and child classification C as predictors of perioperative mortality following elective orthopaedic surgery. Our role is to identify potential patients who present with risk factors for complications and attempt to seek the best determination of treatment strategy for these people.

Excision of pseudotumour in a patient with haemophilia A and inhibitor managed with recombinant factor VIIa

We describe a patient with haemophilia A and factor VIII inhibitor who underwent surgical excision of a large pseudotumour in the left femoral region. Haemostasis was successfully maintained with bolus doses of recombinant factor VIIa at 2-h intervals and anti-fibrinolytic therapy, and the pseudotumour was removed. Subsequently, the dose interval was gradually prolonged to 8 h for a total of 18 days. Although a spontaneous haemorrhage was observed on postoperative day 8, haemostasis was achieved by reducing the dosage interval. No adverse event occurred during the course of treatment.

[Total hip and knee arthroplasty for arthropathy in a hemophiliac]

We evaluated the medium-term follow-up results, effectiveness, and suitability of arthroplasty for hemophilic arthropathy. We performed 26 total knee and 9 total hip arthroplasty operations on hemophilic patients between 1988 and 1998 under general anesthesia and appropriate hemostatic management. Postoperative treatment for hemophilic arthropathy is the same as that for osteoarthritis and rheumatoid arthritis. After their operations, patients experienced relief from pain and intra-articular bleeding in affected joints but only marginal improvement in the range of motion. In general, total joint arthroplasty is not indicated for young patients. However, arthropathy can have a severe impact on the active life of patients during their youth. For severe hemophilic arthritis, total knee and hip arthroplasty can lead to a pain-free and improved quality of life. We believe total knee and hip arthroplasty is a good solutions for hemophiliac arthropathy before severe deformity occurs. Although treated relatively young hemophilic patients, age was not considered to be a contraindication.

[Design of cementless femoral prostheses adaptive to secondary osteoarthritis of the hip joint]

In order to design cementless femoral prostheses for the femoral canal of Japanese patients with secondary osteoarthritis of the hip joint, we analyzed the anatomical features of the hip joint in 85 hips of 55 patients with osteoarthritic hip and 90 hips of 60 subjects with normal hip in three-dimensional CT images. We found that 9 different stem designs varying in width and proximal radius were required to accommodate the hips with secondary osteoarthritis. In normal hips, the anatomical features of the proximal femoral canal to the femoral length was directly proportional. Thus, the values for the proximal radius, the position of the isthmus, off-set value and width of the stem for femoral neck fracture and aseptic necrosis of the femoral head should increase with the stem size, but the ratios of the increase were found different. The mean taper angle from the lower end to the lesser trochanter to the upper end of the isthmus was 3.8 degrees regardless of femoral length.